Protective apparatus



1929- c. J. RODMAN ET AL 1,740,477

PROTECTIVE APPARATUS 4 Original Filed Jan. 16. 1925 WITNESSES: INVENTORSC/are/zce JI/fodmcm and a. W 6hg ves A Sfl/cr' ATTORNEY Patented Dec.24, 1 929 PATENT OFFICE CLABENGE J. BODMAN AND CHARLES A STYER,

OF 'WILKINSBUBG, PENNSYLVANIA,

ASSIGNORS TO WESTINGHOUSE ELECTRIC &. MANUFACTURING COMPANY, A CORPO-m'rron or PENNSYLVANIA rnorncrrvn arrm'rus Application filed January 16,1925, Serial 110.2,779. Renewed Iay 11', 1929.

Our invention relates to oil-insulated electrical devices, such astransformers, and particularly to means for rendering the gases confinedabove the insulating oil inert orfree from oxygen.

One ob]ect of our invention is to provide oil-insulated electricaldevices with means for deoxidizing and dehydrating air or other gasentering therein.

Another object of our invention is to provide a deoxidizing anddehydrating device a for oil-insulated electrical devices that shall beprovided with suitable means for preventing the dehydrating materialfrom rendering the deoxidizing materialdnactive by extracting themoisture therefrom.

A further object of our invention is to pro vide a deoxidizing anddehydrating. device for oil-insulated electrical devices that shall beprovided with a suitably disposed barrier between the deoxidizing anddehydrating materials in order that the dehydratin compound may notdeleteriously afiect t e deoxidizing material by reason of the diifusionof the gases surrounding each material and, at the same time, permittingan exchange 0 air or gas between the two materials under predeterminedconditions.

Still another object of our invention is toprovide a'dehy drating ordeoxidizing device for oil-immersed electrical devices that shall havethe dehydrating compound disposed adjacent to the electrical devices andbe separated from the atmosphere by the deoxidizing device, in "orderthat the moisture of the composition. liberated duringthe activity ofthe deoxidizing compound shall be prevented from entering the electricaldevice.

In the accompanying drawings,

-- Fig. 1 is a view, partially in elevation and partially in section, ofan electrical translating device embodying my invention;

Fig. 2 is a view, partially in elevation and partially in section,valve; and

Fig. 3 is a sectional view of another form of valve.

Our invention comprises, in general, an electrical device 1, such as atransformer or circuit interrupter, that is partially filled f Maude,

of a modified form of with an insulating oil 2, above which is ,confinedan atmosphere 3 of inert or oxygen-free air or gas, and a deoxidizingand dehydrating device 4 for rendering air or gasdrawn into theelectrical device 1 inert or free from oxygen.

The deoxidizing and dehydrating device 4 comprises a casing 5, having asuitable air vent therein and within which are placed containers 6 and 7the latter being disposed within the former, and both of which arecovered by a sealing compound 8 to prevent access of the air thereto.-

The container 6 is filled with a deoxidizing compound9, the compositionof which is approximately The characteristics of the deoxidizingmaterial are described in the application of Rodman, Styer and Wilharm,Serial No. 682,097, filed'Dec. 21, 1923, and which is assigned totheWestinghouse Electric 6% Mann acturing Company.

The container 7 is filled with a dehydrating material 11, such ascalcium. chloride.

A liquid seal 12 is disposed between the atmosphere and the. deoxidizingmaterial 9, in order to prevent unnecessary decomposition of the latterby direct contact with the atmosphere, although the seal 12 permits atransfer of air or gas therethrough under certain conditions of pressureof the gas 3.

The chemical properties of the deoxidizing material 9 are such that aquantity of moisture is required for its chemicalactivity and,accordingly, a certain amount of. moisture is liberated inthe air or gasthat has been treated by it. The dehydrating material 11 is thereforeconnected in series between the deoxidizing material 9 and theelectrical translating device 1. A liquid seal or pressure regu or 13 isconnected between the dehydrating material 11, and the electrical device1, in order that the dehydrating and deoxidizing device 4 may operate atsubstantially air pressure, regardless of the pressure of the gas 3.Inasmuch as the dehydrating material 11 would gradually absorb themoisture contained in the deoxidizing material 9, by reason of thediffusion of the gases surrounding these compounds, it has been foundadvantageous to insert a barrier or check valve 1 1 in the pipeconnection between the deoxidizing and the dehydrating materials.

The check valve 14, shown in Fig. 1, is so disposed as to permit air orgas to be drawn into the electrical device 1, but to prevent the escapeof gas therethrough.

In Fig. 2, a check valve 15 of plate form is shown and may besubstituted in lieu of the check valve 14.

In Fig. 3, there is shown a liquid seal 16 that may be substituted forthe check valve 14:. The advantage of the liquid seal 16 is that itpermits the movement of air or gas in both directions between thechemical compounds 9 and 11. This form of construction is particularlyadvantageous where it is desired to have in-breathing and outbreathingboth take place through the device 4.

During normal operation of an electrical translating device embodyingour invention, the volume of the oil 2 increases and decreases by reasonof changes in temperature, leakage, etc., thereby causing the volume ofthe gas 3 to change. Inasmuch as the temperature of a transformer variesconsiderably from time to time during a single day, as well as withseasonal variations, by reason of the variations in the electricalenergy that it is called upon to transmit, there are many fluctuationsin the volume of the gas 3.

Assuming the temperature, and accordingly the volume, of the oil 2 todecrease, with a corresponding increase in the volume of the gas 3, thepressure in the tank decreases below atmospheric pressure and there is atendency to draw in air from the atmosphere source. Air enters the openend of the pipe leading to the liquid seal 12, traverses the deoxidizingmaterial 9 where its oxygen is removed, check valve 14, the dehydratingmaterial 11 wherein its moisture is absorbed and the pressure regulator13 to the gas 3. The product entering the tank 1 is accordinglysubstantially pure dry nitrogen. The pressure regulator is so adjustedthat, when the pressure within the electrical device 1 drops slightlybelow that of the surrounding atmosphere, an inbreathing action takesplace in order to prevent oXygen-bearing air being drawn in around theseams of the device 1.

Upon a decrease in the volume of the at-" mosphere 3, the check valve 14prevents the out-breathing of gas from the device 1, and

Fig. 3, is employed, the escaping gas travv erses the pressure regulator13, the dehydrating material 11, the valve 16, the deoxidizing material9 and the liquid seal 12 in a direction opposite to that shown by thearrows. The pressure regulator 13 is so ad justed as to require aconsiderable pressure of the atmosphere 3 to be present beforepermitting out-breathing.

It will thus be seen that we have devised a dehydrating and deoxidizingdevice in which the advantages inherent to the deoxidizing compound andthe dehydrating compound are utilized without permitting the moisture,incidental to the operation of-the deoxidizing compound, to enter theelectrical devices and, at the same time, preventing the dehydratingcompound from unnecessarily rendering the deoxidizing compound inactiveby absorbing the moisture therefrom by reason of diffusion of gastherebetween.

While we have illustrated but one embodiment of our invention, it willbe apparent to those skilled in the art that various changes andmodifications may be made in the apparatus illustrated without departingfrom the spirit and scope of our invention, as set forth in the appendedclaims.

We claim as our invention:

1. In combination, an electrical device comprising a casing, adeoxidizing compound and a dehydrating compound disposed between theatmosphere and the casing in the order named, and means for sealing saidcompounds from each other under predetermined conditions.

2. In combination, an electrical device comprising a casing, adeoxidizing compound and a dehydrating compound disposed between theatmosphere and the casing in the order named, and means for sealing saidcompounds from each other under predetermined conditions, said sealingmeans permitting a transfer of air or gas between said compounds underother conditions.

3. In combination, an electrical device comprising a casing, a moistdeoxidizing comorder named, and means for preventing the absorption ofthe moisture from the deoxidizing material under certain conditions,said means permitting a transfer of air or gas between said compoundsunder other conditions 5. In combination, an electrical devicecomprising a casing, a'moist deoxidizing compound and a dehydratingcompound disposed between the atmosphere and the casing in the ordernamed and means for preventing the absorption of the moisture from thedeoxidizing material under certain conditions, said means permitting atransfer ofair or, gas to the casing under other conditions, wherebysaid deoxidized air or gas is brought into contact with the dehydratingcompound before entering the casing. r

6. The combination of a casing, a moist deoxidizing compound and adehydrating compound, the dehydrating compound being so disposedrelative to the casing and the deoxidizing compound as to remove thehygroscopic moisture from all air or gas entering the casing, of meansfor preventing the absorption of the moisture from the deoxidizingcompoundunder certain conditions. I

7 The combination with an interconnect ed deoxidizing compound of amoist material and dehydrating compound, of means for preventing thedehydrating compound from absorbing the moisture of the deoxidizingmaterial, said means permitting the interchange of air or gas betweensaid compounds under predetermined conditions.

; 8. The combination with an interconnected deoxidizing compound of amoist material and a dehydrating compound, of means for preventing thedehydrating compound from absorbing the moisture of the deoxidizing Imaterial.

9. The combination with a deoxidizing compound having a moistened air orgas in contact therewith and a dehydrating compound in series connectiontherewith, of

{means for preventing the absorption of the hygroscopic moistureadjacent to the deoxidlzing compound by the dehydrating compound, saidmeans permitting an exchange of air or gas between said compounds underabnormal conditions.

In testimony whereof, we have hereunto subscribed our names this 18thday of December, 1924.

CLARENCE J. RODMAN.

5 CHARLES A. STYER.

